U.S. patent application number 10/297474 was filed with the patent office on 2004-02-05 for multiplexed signal quality display, method, and program, and recorded medium where the program is recorded.
Invention is credited to Ichikawa, Hideki, Koizumi, Satoshi, Nakada, Juichi, Nishino, Eiji.
Application Number | 20040022182 10/297474 |
Document ID | / |
Family ID | 26593633 |
Filed Date | 2004-02-05 |
United States Patent
Application |
20040022182 |
Kind Code |
A1 |
Koizumi, Satoshi ; et
al. |
February 5, 2004 |
Multiplexed signal quality display, method, and program, and
recorded medium where the program is recorded
Abstract
Since a multiplexed signal quality display system according to
the present invention is provided with a memory means which stores
measurement results obtained by measuring electric powers of
signals present in all of channels within a band used and a display
means which specifies a channel where the presence of a signal is
predicted and which reads and displays the measured value of the
specified channel, it is possible to display the waveform quality
of a channel which is determined by desired Walsh code and Walsh
code length.
Inventors: |
Koizumi, Satoshi; (Tokyo,
JP) ; Nakada, Juichi; (Tokyo, JP) ; Nishino,
Eiji; (Tokyo, JP) ; Ichikawa, Hideki; (Tokyo,
JP) |
Correspondence
Address: |
LOWE HAUPTMAN GILMAN AND BERNER, LLP
1700 DIAGONAL ROAD
SUITE 300 /310
ALEXANDRIA
VA
22314
US
|
Family ID: |
26593633 |
Appl. No.: |
10/297474 |
Filed: |
August 15, 2003 |
PCT Filed: |
June 8, 2001 |
PCT NO: |
PCT/JP01/04844 |
Current U.S.
Class: |
370/208 ;
375/E1.002 |
Current CPC
Class: |
H04B 17/309 20150115;
H04L 1/24 20130101; H04B 1/707 20130101; H04J 13/0048 20130101;
H04B 17/23 20150115 |
Class at
Publication: |
370/208 |
International
Class: |
H04J 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 2000 |
JP |
2000-173484 |
Jun 12, 2000 |
JP |
2000-175177 |
Claims
What is claimed is:
1. A multiplexed signal quality display system for measuring the
quality of a multiplexed signal issued from a communication device
wherein a band width to be used and the number of communication
channels capable of being accommodated are determined by a
diffusion code length, the number of communication channels and
channels to be used, which are determined by a diffusion code
length, are decided in terms of a diffusion code number affixed to
the type of the diffusion code, to effect communication while
ensuring multi-channel communication lines in one and same band,
said system comprising: a memory means for storing measurement
results obtained by measuring electric powers of signals present in
all of the channels within the band used; and a display means which
specifies a channel where the presence of a signal is predicted and
reads and displays a measured value in the specified channel.
2. A multiplexed signal quality display system according to claim
1, wherein said memory means stores a phase difference or a delay
difference of each said channel, and said display means reads the
phase difference or the delay difference of each said channel from
said memory means and displays it.
3. A multiplexed signal quality display system according to claim
1, wherein said memory means stores an electric power of a signal
and a noise component power of the signal, and said display means
displays a graph having a length proportional to the values of said
electric power of the signal and a graph having a length
proportional to the value of said noise component power of the
signal in such a manner that in a longitudinal direction of one of
said graphs there is disposed the other graph.
4. A multiplexed signal quality display system for measuring the
quality of a multiplexed signal issued from a communication device
wherein a band width to be used and the number of communication
channels capable of being accommodated are determined by a
diffusion code length, the number of communication channels and
channels to be used, which are determined by a diffusion code
length, are decided in terms of a diffusion code number affixed to
the type of the diffusion code, to effect communication while
ensuring multi-channel communication lines in one and same band,
said system comprising: an updating means which initializes a
diffusion code length and a diffusion code number defined for each
diffusion code length and which makes updating from the initialized
values up to predetermined final values; a diffusion code
generating means which generates a diffusion code in accordance
with the diffusion code length and diffusion code number generated
by said updating means; a demodulator means which demodulates the
signal in each said channel in accordance with the diffusion code
generated by said diffusion code generating means and said
diffusion code length and said diffusion code number; a power
coefficient calculator which calculates a power coefficient of the
signal demodulated by said demodulator means; a memory which stores
the power coefficient of each said channel calculated by said power
coefficient calculator in accordance with the diffusion code length
and the diffusion code number; a setting means which reads a power
coefficient from among the power coefficients stored in said memory
while specifying desired diffusion code and diffusion code number;
a graphing means which converts the power coefficient read by said
setting means into a power value, determines a length in Y-axis
direction in accordance with said power value, and forms a
strip-like display region; an image memory which stores image data
graphed by said graphing means; and a calculation result display
means which displays the image stored in said image memory.
5. A multiplexed signal quality display method for measuring the
quality of a multiplexed signal issued from a communication device
wherein a band width to be used and the number of communication
channels capable of being accommodated are determined by a
diffusion code length, the number of communication channels and
channels to be used, which are determined by a diffusion code
length, are decided in terms of a diffusion code number affixed to
the type of the diffusion code, to effect communication while
ensuring multi-channel communication lines in one and same band,
said method comprising: a storing step for storing measurement
results obtained by measuring electric powers of signals present in
all of the channels within the band used; and a display step which
specifies a channel where the presence of a signal is predicted and
reads and displays a measured value in the specified channel.
6. A program of instructions for execution by the computer to
perform a multiplexed signal quality display process for measuring
the quality of a multiplexed signal issued from a communication
device wherein a band width to be used and the number of
communication channels capable of being accommodated are determined
by a diffusion code length, the number of communication channels
and channels to be used, which are determined by a diffusion code
length, are decided in terms of a diffusion code number affixed to
the type of the diffusion code, to effect communication while
ensuring multi-channel communication lines in one and same band,
said multiplexed signal quality display process comprising: a
storing process for storing measurement results obtained by
measuring electric powers of signals present in all of the channels
within the band used; and a display process which specifies a
channel where the presence of a signal is predicted and reads and
displays a measured value in the specified channel.
7. A computer-readable medium having a program of instructions for
execution by the computer to perform a multiplexed signal quality
display process for measuring the quality of a multiplexed signal
issued from a communication device wherein a band width to be used
and the number of communication channels capable of being
accommodated are determined by a diffusion code length, the number
of communication channels and channels to be used, which are
determined by a diffusion code length, are decided in terms of a
diffusion code number affixed to the type of the diffusion code, to
effect communication while ensuring multi-channel communication
lines in one and same band, said multiplexed signal quality display
process comprising: a storing process for storing measurement
results obtained by measuring electric powers of signals present in
all of the channels within the band used; and a display process
which specifies a channel where the presence of a signal is
predicted and reads and displays a measured value in the specified
channel.
Description
FIELD OF ART
[0001] The present invention relates to displaying the waveform
quality of a multiplexed signal such as CDMA signal.
BACKGROUND ART
[0002] The applicant in the present case has previously proposed
such a CDMA signal waveform quality measuring method as disclosed
in Japanese Patent Laid Open No. 173628/1998. FIG. 7 shows an
example of power display of various channels as measured by the
measuring method disclosed therein.
[0003] In FIG. 7, electric power W is plotted along the axis of
ordinate, while channels CH are plotted along the axis of abscissa.
In the example of FIG. 7, Walsh code length is set at "64" to
permit connection of 64-channel lines, and a state is shown in
which channels 0, 1, 3, 5, 7, 9, 11, 13 . . . 61, and 63 are
generating signals.
[0004] In the example shown in FIG. 7 it is proposed to merely fix
Walsh code length to "64" and measure the waveform quality of CDMA
signal. As to Walsh length of CDMA signal presently in use in
portable telephone, a standard which permits change-over to six
lengths of 4, 8, 16, 63, and 128 is under consideration.
[0005] A band width is set in a transmission line by Walsh code
length and a channel number is determined by Walsh code. FIG. 8
shows a relation between Walsh code length as diffusion code length
and Walsh code as diffusion code. L=4, L=8, L=16, . . . shown in
the left column represent Walsh lengths. At Walsh code length L=4,
a predetermined band AF is divided into four and four channels of
0, 1, 2, 3 are allocated thereto. The channel numbers 0-3 of the
four channels are given in terms of Walsh code numbers 0, 1, 2, and
3.
[0006] As is seen from FIG. 8, as Walsh code length becomes larger,
the number of employable channels increases in a doubly increasing
relation and an employable band width becomes narrower in
decrements of 1/2. From this relation it will be seen that a short
Walsh code length is allocated to a telephone set which handles a
large volume of data to be transmitted, while a long Walsh code
length is allocated to a telephone set which handles a small volume
of data. In FIG. 8, Walsh code lengths 64 and 128 are omitted.
[0007] Thus, in the actual base station, a Walsh code length is
selected from among six Walsh code lengths of L=4 to L=128 in
accordance with the communication band width which the telephone
set concerned requires, and a Walsh code not in use is selected and
is used. Therefore, it is necessary to test whether all the
channels in all the Walsh code lengths are in normal operation or
not.
[0008] Therefore, also in the waveform quality measuring system it
is necessary that the waveform quality be measured for all Walsh
codes in all Walsh code lengths.
[0009] It is an object of the present invention to provide a CDMA
signal waveform quality measuring system which, no matter which
Walsh code length defined in the standard may be used in the
issuance of CDMA signal, can determine the waveform quality of the
signal.
DISCLOSURE OF THE INVENTION
[0010] The present invention as described in claim 1, is a
multiplexed signal quality display system for measuring the quality
of a multiplexed signal issued from a communication device wherein
a band width to be used and the number of communication channels
capable of being accommodated are determined by a diffusion code
length, the number of communication channels and channels to be
used, which are determined by a diffusion code length, are decided
in terms of a diffusion code number affixed to the type of the
diffusion code, to effect communication while ensuring
multi-channel communication lines in one and same band, the system
including: a memory unit for storing measurement results obtained
by measuring electric powers of signals present in all of the
channels within the band used; and a display unit which specifies a
channel where the presence of a signal is predicted and reads and
displays a measured value in the specified channel.
[0011] The present invention as described in claim 2, is a
multiplexed signal quality display system according to claim 1,
wherein the memory unit stores a phase difference or a delay
difference of each the channel, and the display unit reads the
phase difference or the delay difference of each the channel from
the memory unit and displays it.
[0012] The present invention as described in claim 3, is a
multiplexed signal quality display system according to claim 1,
wherein the memory unit stores an electric power of a signal and a
noise component power of the signal, and the display unit displays
a graph having a length proportional to the values of the electric
power of the signal and a graph having a length proportional to the
value of the noise component power of the signal in such a manner
that in a longitudinal direction of one of the graphs there is
disposed the other graph.
[0013] The present invention as described in claim 4, is a
multiplexed signal quality display system for measuring the quality
of a multiplexed signal issued from a communication device wherein
a band width to be used and the number of communication channels
capable of being accommodated are determined by a diffusion code
length, the number of communication channels and channels to be
used, which are determined by a diffusion code length, are decided
in terms of a diffusion code number affixed to the type of the
diffusion code, to effect communication while ensuring
multi-channel communication lines in one and same band, the system
including: an updating unit which initializes a diffusion code
length and a diffusion code number defined for each diffusion code
length and which makes updating from the initialized values up to
predetermined final values; a diffusion code generating unit which
generates a diffusion code in accordance with the diffusion code
length and diffusion code number generated by the updating unit; a
demodulator unit which demodulates the signal in each the channel
in accordance with the diffusion code generated by the diffusion
code generating unit and the diffusion code length and the
diffusion code number; a power coefficient calculator which
calculates a power coefficient of the signal demodulated by the
demodulator unit; a memory which stores the power coefficient of
each the channel calculated by the power coefficient calculator in
accordance with the diffusion code length and the diffusion code
number; a setting unit which reads a power coefficient from among
the power coefficients stored in the memory while specifying
desired diffusion code and diffusion code number; a graphing unit
which converts the power coefficient read by the setting unit into
a power value, determines a length in Y-axis direction in
accordance with the power value, and forms a strip-like display
region; an image memory which stores image data graphed by the
graphing unit; and a calculation result display unit which displays
the image stored in the image memory.
[0014] The present invention as described in claim 5 is a
multiplexed signal quality display method for measuring the quality
of a multiplexed signal issued from a communication device wherein
a band width to be used and the number of communication channels
capable of being accommodated are determined by a diffusion code
length, the number of communication channels and channels to be
used, which are determined by a diffusion code length, are decided
in terms of a diffusion code number affixed to the type of the
diffusion code, to effect communication while ensuring
multi-channel communication lines in one and same band, the method
including: a storing step for storing measurement results obtained
by measuring electric powers of signals present in all of the
channels within the band used; and a display step which specifies a
channel where the presence of a signal is predicted and reads and
displays a measured value in the specified channel.
[0015] The present invention as described in claim 6 is a program
of instructions for execution by the computer to perform a
multiplexed signal quality display process for measuring the
quality of a multiplexed signal issued from a communication device
wherein a band width to be used and the number of communication
channels capable of being accommodated are determined by a
diffusion code length, the number of communication channels and
channels to be used, which are determined by a diffusion code
length, are decided in terms of a diffusion code number affixed to
the type of the diffusion code, to effect communication while
ensuring multi-channel communication lines in one and same band,
the multiplexed signal quality display process including: a storing
process for storing measurement results obtained by measuring
electric powers of signals present in all of the channels within
the band used; and a display process which specifies a channel
where the presence of a signal is predicted and reads and displays
a measured value in the specified channel.
[0016] The present invention as described in claim 7 is a
computer-readable medium having a program of instructions for
execution by the computer to perform a multiplexed signal quality
display process for measuring the quality of a multiplexed signal
issued from a communication device wherein a band width to be used
and the number of communication channels capable of being
accommodated are determined by a diffusion code length, the number
of communication channels and channels to be used, which are
determined by a diffusion code length, are decided in terms of a
diffusion code number affixed to the type of the diffusion code, to
effect communication while ensuring multi-channel communication
lines in one and same band, the multiplexed signal quality display
process including:
[0017] a storing process for storing measurement results obtained
by measuring electric powers of signals present in all of the
channels within the band used; and
[0018] a display process which specifies a channel where the
presence of a signal is predicted and reads and displays a measured
value in the specified channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a block diagram showing the construction of a
multiplexed signal waveform quality display system according to a
first embodiment of the present invention;
[0020] FIG. 2 is a diagram showing arithmetic expressions;
[0021] FIG. 3 is a flow chart showing the operation of an updating
means 34 which executes initializing and updating operations of
Walsh code length and Walsh code, and also showing in what sate
arithmetic processings are performed in various components;
[0022] FIG. 4 is a diagram showing a display screen in the first
embodiment;
[0023] FIG. 5 is a diagram showing a display screen according to a
modification in the first embodiment;
[0024] FIG. 6 is a diagram showing a display screen according to a
modification in a second embodiment of the present invention;
[0025] FIG. 7 is a diagram showing a conventional display screen;
and
[0026] FIG. 8 is a diagram showing a relation between Walsh code
length as diffusion code length and Walsh code as diffusion code in
the prior art.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Embodiments of the present invention will be described
hereinunder with reference to the accompanying drawings.
[0028] First Embodiment
[0029] FIG. 1 shows an example of multiplexed signal waveform
quality display system according to the present invention.
[0030] In FIG. 1, a frequency-diffused, multi-channel CDMA signal
from a base station is inputted through an input terminal 11 and is
converted to an intermediate frequency signal by means of a down
converter 12. The intermediate frequency signal is amplified by an
amplifier 13, then is band-limited by a filter 14, and is
thereafter converted to a digital signal by an A/D converter 15.
The digital intermediate frequency signal from the A/D converter 15
is converted to a base band signal by an orthogonal transformer 17
which includes a complementary filter, affording a base band
measurement signal Z(k).
[0031] The base band measurement signal Z(k) is inverse-diffused in
a demodulator 25 with a diffusion code (Walsh code) provided from a
diffusion code generator 20 and bit data is demodulated for each
channel. At the same time, amplitude a'i (i is channel number) of
each channel is detected.
[0032] In an ideal signal generator 26, an ideal signal Ri (i is
channel number) is produced on the basis of both bit data provided
from the demodulator 25 and diffusion code PN (Walsh code) provided
from the diffusion code generator 20. Further, in accordance with
the ideal signal Ri, the following expressions are calculated to
generate correction data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k): 1 A
i ( k ) = a i ' [ m = - M M a ( m ) R i ( k - m ) ] j i ' ( 1 ) B i
( k ) = { 2 a i ' [ m = - M M a ( m ) R i ( k - m ) ] i ' + a i ' [
m = - M M b ( m ) R i ( k - m ) ] } j i ' ( 2 ) C i ( k ) = { a i '
[ m = - M M a ( m ) R i ( k - m ) ] i '2 + a i ' [ m = - M M b ( m
) R i ( k - m ) ] i ' + a i ' [ m = - M M c ( m ) R i ( k - m ) ] }
j i ' ( 3 ) I i ( k ) = { [ m = - M M a ( m ) R i ( k - m ) ] i '2
+ [ m = - M M b ( m ) R i ( k - m ) ] i ' + [ m = - M M c ( m ) R i
( k - m ) ] } j i ' ( 4 ) H i ( k ) = { 2 [ m = - M M a ( m ) R i (
k - m ) ] i ' + [ m = - M M b ( m ) R i ( k - m ) ] } j i ' ( 5
)
[0033] The ideal signal Ri is obtained in the following manner.
Demodulated bit data of channels i provided from the demodulator 25
are inverse-diffused with I- and Q-side diffusion codes (Walsh
codes) provided from the diffusion code generator 20, then chips
"0" and "1" in the thus inversion-diffused I- and Q-side chip rows
are converted to +{square root}2 and -{square root}2, respectively
to afford I and Q signals of QPSK signal with an amplitude of 1.
That is, using the ideal signal Ri(k.multidot.m) with a normalized
amplitude and the amplitude a'i from the demodulator 25, there are
calculated auxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and
Hi(k).
[0034] The auxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k) and
the measurement signal Z(k) are inputted to a parameter estimator
27, in which simultaneous equations shown in FIG. 2 are solved and
estimate values .DELTA.ai, .DELTA..SIGMA.i, .DELTA..theta.i, and
.DELTA..omega. are obtained as solutions thereof. Using these
estimate values, the correction parameters so far used a'i,
.tau.'i, .theta.'i, and .omega.' are updated as follows in a
transformer 28:
.omega.'.rarw..omega.'+.DELTA..omega.
.alpha.'i.rarw.a'i+.DELTA.ai
.tau.'i.rarw..tau.'i+.DELTA..tau.i
.theta.'i.rarw..theta.'i+.DELTA..theta.i (6)
[0035] Then, using the thus-corrected parameters a'i, .tau.'i,
.theta.'i, and .omega.', correction is made for the measurement
signal Z(k) and the thus-corrected measurement signal Z(k) is again
subjected to the processings in the demodulator 25, the ideal
signal/auxiliary data generator 26, the parameter estimator 27, and
the transformer 28. These processings are carried out until the
estimate values .DELTA.ai, .DELTA..tau.i, .DELTA..theta.i, and
.DELTA..omega. are optimized, that is, until reaching zero or near
zero, or until there occurs no change of value ever with
repetition. By this optimizing step, correction is made not only
for the measurement signal Z(k) but also for the ideal signal
Ri.
[0036] Therefore, an optimizing means 22 is constituted by the
orthogonal transformer 17 which includes a complementary filter,
the demodulator 25, the ideal signal generator 26, the parameter
estimator 27, and the transformers 28 and 29.
[0037] Correction for the measurement signal Z(k) is made as
follows relative to Z(k) of the last time:
Z(k).rarw.Z(t-.tau.'0)(1/a'0)
exp[-j(.omega.'(t-.tau.'0)+.theta.'0)] (7)
[0038] As initial values are set a'0=1, .tau.'0=0, .theta.'0=0, and
.omega.'=0, and each time estimate values are obtained in the
parameter estimator 27, the expression (7) is calculated with
respect to new a'i, .tau.'i, .theta.'i, and .omega.'. That is, this
calculation for correction is made for the signal inputted to the
orthogonal transformer/complementary filter 17, i.e., the output of
the A/D converter 15.
[0039] The calculation for correction may be performed for the
measurement signal Z(k) after conversion to the base band. However,
this base band-converted signal is a signal after having passed the
complementary filer (the same pass band width as the band width of
the input signal). If there is a gross frequency error, this filter
processing may result in that a portion of the signal is removed,
that is, the measurement signal to be used in parameter estimation,
etc., is chipped. Therefore, the result of the frequency estimation
is corrected at a stage which precedes the complementary filter.
But the correction may be made for the measurement signal after
conversion to the base band, provided there is used a low pass
filter of a sufficiently wide band without using the complementary
filter in the orthogonal transformer/complementary filter 17.
[0040] The correction parameters a'i, .tau.'i, and .theta.'i are
subjected to the following conversion in the transformer 29:
a"i=a'i/a'0
.tau."i=.tau.'i-.tau.'0
.theta.'i=.theta.'i-.theta.'0 provided i.noteq.0 (8)
[0041] As to the measurement signal Z(k), since the parameters of
the 0.sup.th channel are corrected by the expression (7), the
parameters for correcting the 0.sup.th ideal signal R.sub.0 are
normalized into the following values:
a"0=1
.tau."0=0
.theta."0=0
[0042] The parameters for the ideal signal Ri of channels other
than the 0.sup.th channel are corrected by 0.sup.th parameters as
in the expression (8).
[0043] That is, in the first repetition in the foregoing
optimization step, correction for the measurement signal Z(k) is
made using the correction parameters of the 0.sup.th channel and
therefore, as correction parameters used in the auxiliary data
generator 26, there is used the expression (8) normalized by the
parameters of the 0.sup.th channel, i.e., a transformed output of
the transformer 29. More particularly, the calculations of the
expressions (1) to (5) are performed using parameters which are
conceivable in the expression (8) to determine auxiliary data
Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k). In this calculation for
determining auxiliary data there are used bit data and amplitude
a'i, the bit data being obtained as a result of demodulating Z(k)
in the demodulator 25 after correction by the expression (7).
[0044] Thus, both corrections described above are performed every
time estimate values are obtained from the parameter estimator 27,
and the estimation of parameters is again repeated until
optimization of the estimate values, whereupon a power coefficient
.rho.i is calculated and determined as follows in a power
coefficient calculator 31, using measurement signal Z(k) and
diffusion code (Walsh code) obtained at that instant: 2 i = j = 1 N
k = 1 64 Z j k R i j k * 2 { k = 1 64 R i j k 2 } { j = 1 N k = 1
64 Z j k 2 } ( 9 )
[0045] The expression (9) is the same as the expression defined by
the CDMA signal measurement standard and used in the prior art.
[0046] The following calculation is performed in a transformer
32:
a{circumflex over ( )}=a'
.DELTA..tau.{circumflex over ( )}i=.tau.'i-.tau.'0
.DELTA..theta.{circumflex over ( )}i=.theta.'i-.theta.'0
.DELTA..omega.{circumflex over ( )}=.omega.' (10)
[0047] The parameters a{circumflex over ( )},
.DELTA..tau.{circumflex over ( )}i, .DELTA..theta.{circumflex over
( )}i, .DELTA..omega.{circumflex over ( )}, .tau.{circumflex over (
)}0, and the power coefficient .rho.i obtained in the power
coefficient calculator 31 are displayed on a display 33.
[0048] As described above, the measurement signal Z(k) and the
ideal signal Ri are corrected using estimated parameters, and the
estimation of parameters is again performed using both corrected
signals until optimization of the estimated parameters. Since all
the parameters are used in this optimization, all the parameters
are optimized, and after the optimization, the power coefficient
.rho.i is determined using the measurement signal, so that the
power coefficient .rho.i can be obtained with a high accuracy.
Other parameters are also determined with a high accuracy because
the measurement signal is included in the optimization loop.
[0049] The multiplexed signal waveform quality display system of
the first embodiment is further provided with an updating means 34
and a memory 33A.
[0050] The updating means 34 initializes the value of Walsh code
length as diffusion code length and code number of Walsh code as
diffusion code and updates the values of Walsh code length and
Walsh code successively from the initialized values.
[0051] While the initialized values of Walsh code length and Walsh
code are updated successively by the updating means 34, there are
calculated waveform quality parameters with respect to all the
Walsh code lengths and Walsh codes defined by the CDMA signal
standard.
[0052] The memory 33A stores the result of the calculation. The
multiplexed signal waveform quality display system according to the
first embodiment is further provided with a setting means 35, a
graphing means 33B, an image memory 33C, and a calculation result
display 33D.
[0053] FIG. 3 shows the operation of the updating means 34 which
executes Walsh code length, Walsh code initializing and updating
operations, and also shows in what state arithmetic processings are
performed in various components.
[0054] In step SP1, Walsh code length is initialized at L=4. In
step SP2, the number assigned to Walsh code (corresponding to
channel number) is set at i=0.
[0055] In step SP3, an ideal signal Ri.multidot.L based on Walsh
code length L=4 and Walsh code i=0 is produced in the ideal signal
generator 26.
[0056] In step SP4, parameters are estimated in the parameter
estimator 27 in accordance with the ideal signal Ri.multidot.L and
are then fed back to the orthogonal transformer 17 for optimization
processing. Then, the power coefficient .rho.i.multidot.L is
calculated on the basis of the measurement signal Z(k) after
optimization processing and the diffusion code.
[0057] In step SP5, the power coefficient .rho.i.multidot.L
calculated in step SP4 and other parameters 'ai.multidot.L,
.DELTA.'.tau.i.multidot.L, .DELTA.'.theta.i.multidot.L,
.DELTA.'.omega., .tau.0' are stored in the memory 33A.
[0058] In step SP6, the value of Walsh code i is updated as i+1,
then in step SP7, the value of Walsh code length L and that of
Walsh code i are compared with each other. If both disagree, the
processing flow returns to step SP3. That is, in case of Walsh code
length L=4, i=4 results from executing the steps SP3-SP7 four
times, and the flow advances to step SP8.
[0059] In step SP8, the value L of Walsh code length is doubled for
updating to L=8. In step SP9, a check is made to see if the value L
of Walsh code length has become larger than the maximum value 128.
If the answer is affirmative, the flow returns to step SP2.
[0060] In step SP2, initialization is made again to i=0 and the
routine of steps SP3-SP7 is executed. With L=8, the routine of
steps SP3-SP7 is executed eight times. In this eight-time
execution, power coefficients .rho.i.multidot.L and parameters
{circumflex over ( )}ai.multidot.L, .DELTA..tau.{circumflex over (
)}i.multidot.L, .DELTA..theta.{circumflex over ( )}i.multidot.L,
.DELTA.{circumflex over ( )}.omega., .tau.0' for eight channels of
0-7 defined for Walsh code length of L=8 are calculated and are
stored in the memory 33A.
[0061] In this way the Walsh code length L is updated in the order
of 4, 8, 16, 32, 64, and 128, and power coefficient
.rho.i.multidot.L and parameters {circumflex over (
)}ai.multidot.L, .DELTA..tau.{circumflex over ( )}i.multidot.L,
.DELTA..theta.{circumflex over ( )}i.multidot.L, .DELTA.{circumflex
over ( )}.omega., .tau.0' are stored in the memory 33A for each
channel determined by each Walsh code length L.
[0062] If it is detected in step SP9 that the value L of Walsh code
length has exceeded the maximum value of 128, the processing flow
branches to step SP10.
[0063] In step SP10, an electric power of each channel is
calculated from, for example, power coefficient .rho.i included in
the measurement results of each channel and in accordance with an
address which is determined by a desired to-be-displayed channel
number set in the setting means 35, and this power value is
inputted to the graphing means 33B. The graphing means 33B
determines the height of a bar graph to be displayed at the display
position of each channel correspondingly to the power value of each
channel, and causes image data of the bar graph to be stored in the
image memory 33C. The calculation result display 33D reads the bar
graph data from the image memory 33C and displays the bar
graph.
[0064] Power W can be calculated as follows from the power
coefficient .rho.i.multidot.L:
W=10.0.times.log.sub.10(.rho.i.multidot.L)
[0065] This calculation can be done in the graphing means 33B for
example.
[0066] For example, therefore, if i=0, 1, 2, . . . 7 are set at
Walsh code length L=8 and the operation mode is set to a mode of
displaying electric powers of signals present in 0-7 channels, it
is possible to display the electric power W of CDMA signal present
on each of eight-channel transmission lines, as shown in FIG.
4.
[0067] At this time, it is necessary that Walsh code length L be
sure to be known as L=8 with respect to the signal to be measured.
Thus, the value of Walsh code length L and the channel which
outputs the signal are known in advance, so by setting the known
value in the setting means 35 and if a spectrum which reflects it
as it is, it can be judged that the base station is operating
normally.
[0068] As shown in FIG. 4, Walsh code length (L=8) is displayed in
a numerical value display column 40. Parameters .DELTA..tau. and
.DELTA..theta. (or .DELTA..tau.{circumflex over ( )} and
.DELTA..theta.{circumflex over ( )}) may be displayed in the
numerical value display column 40, as shown in FIG. 5. The
parameters .DELTA..tau. and .DELTA..tau.{circumflex over ( )} stand
for a delay difference of each channel, while the parameters
.DELTA..theta. and .DELTA..theta.{circumflex over ( )} stand for a
phase difference of each channel.
[0069] Although in the example shown in FIG. 5 electric power W is
displayed along the axis of ordinate, parameters .DELTA..tau. and
.DELTA..theta. (or .DELTA..tau.' and .DELTA..theta.{circumflex over
( )}) may be displayed along the axis of ordinate.
[0070] Second Embodiment
[0071] This second embodiment is different from the first
embodiment in point of displaying a noise power component. A
description will be given below only about the different point.
[0072] Noise power coefficient .rho..sub.Ni (code Domain Error) is
calculated as follows by the power coefficient calculator 31 using
Z.sub.j.multidot.k and Ri.multidot.j.multidot.k in the expression
(9).
[0073] The sum of channels in the ideal signal Ri is subtracted
from the measurement signal Z to obtain an error signal N, and a
power coefficient is determined as follows with respect to the
error signal N: 3 N i k = Z j k - i L - 1 R i j k N i = j = 1 ( M /
L ) k = 1 L N j k .times. R i j k * 2 { k = 1 L R i j k 2 } { j = 1
( M / L ) k = 1 L Z j k 2 }
[0074] Noise power W.sub.N of i channel is calculated as
follows:
W.sub.N=10.0.times.log.sub.10(.rho..sub.Ni)
[0075] The result of the calculation is stored in the memory 33A in
a pair with the signal power W.sub.S channel by channel. The values
of signal power W.sub.S and noise power W.sub.N in each channel are
graphed by a graph plotting means (included in the calculation
result display 33) and written as a graph in an image memory. The
values of signal power W.sub.S and noise power W.sub.N in all the
channels are all stored in the image memory, whereby the states of
all the channels are displayed on the display.
[0076] FIG. 6 shows an example of the plotting. In the same figure,
hatched portions (graphs) with solid lines represent signal powers
W.sub.S of the channels, while dotted line portions (graphs)
represent noise powers W.sub.N of the channels. The height (length)
of each graph represents the signal power W.sub.S and noise power
W.sub.N of each channel. The graphs of noise power W.sub.N underlie
vertical (longitudinal) extension lines of the graphs of signal
power W.sub.S.
[0077] According to the present invention, as set forth above, the
measurement of waveform quality is conducted with respect to all
the channels defined by the CDMA signal standard and the results of
the measurement are stored in the memory 33A, so that by setting in
the setting means 35 both Walsh code length and Walsh code given as
known values from among the stored values for which a signal is
being issued at present, then by reading a power coefficient
specified by the setting means 35, as well as parameters, and
inputting the thus-read power coefficient and parameters to the
calculation result display 33D, it is possible to display the
waveform quality of the channel which is determined by desired
Walsh code length and Walsh code.
[0078] Thus, by using the system of the invention in case of
adjusting, for example, a base station for portable telephone to be
tested, there can be obtained an advantage that the time and labor
required for the adjustment can be greatly reduced.
* * * * *